1. Field of the Invention The present invention relates generally to devices for providing access by a dialysis machine and, more specifically, to implantable hemodialysis ports which provide a cosmetically appealing dialysis adapter port for long term dialysis patients which are easily located and prevent the need for repeatedly performing surgery to relocate arteriovenous fistulas and external shunts due to scarring, vein damage and clotting.
2. Description of the Prior Art
Presently, two methods of performing dialysis on a patient are utilized. These methods are peritoneal dialysis and hemodialysis. Peritoneal dialysis is outside the scope of the present invention. In hemodialysis, blood is removed from the body and pumped through a machine. The blood is passed through a membrane in the machine which acts to remove any toxins from the blood prior to returning the blood to the patient. Hemodialysis is performed utilizing any of three possible surgical procedures.
A first of these surgical procedures involves forming an arteriovenous fistula between an artery and a vein, usually in the arm of the patient. The forming of the fistula causes the vein to enlarge thus making it ideal for the insertion of a catheter. With this method the vein must be repeatedly pierced. The repeated piercing of the vein causes scar tissue to develop and eventually leads to clotting within the fistula. When this occurs the surgery to insert a new fistula replacing the old fistula must be performed again.
Furthermore, as the kidney's of the patient are unable to remove waste, the veins are caused to become inflamed and thus it is difficult to find a suitable vein for insertion of the fistula.
A second surgical procedure involves using an externally extending shunt consisting of a tube for connecting and providing access to an implanted catheter. This procedure imposes a burden on the patient as the shunt extends outside of the body and is subject to infection. Furthermore, this procedure does not prevent clotting of the catheter and thus the patient may frequently need to have the catheter cleaned or replaced.
The third surgical procedure involves insertion of a totally implantable adapter device into the body of the patient. This procedure is an improvement over the previously discussed procedures as it prevents infection and provides a more durable platform for performing hemodialysis. However, this procedure is susceptible to clotting either due to the condition of the patient or oversight of the health care technician who fails to flush the catheter after each dialysis session.
Numerous types of dialysis access ports have been provided in the prior art. For example, U.S. Pat. Nos. 5,405,320; 5,480,380; 5,509,897 and 5,562,617 all are illustrative of such prior art. While these units may be suitable for the particular purpose to which they address, they would not be as suitable for the purposes of the present invention as heretofore described.